Novel fluorinated compounds and process for preparing them

ABSTRACT

By reacting 3,3,4,4-tetrafluoro-2-(trifluoromethyl)-1,2-oxazetidine (I) with a Lewis acid, in particular SbF 5 , three novel fluorinated compounds (II), (III) and (IV) are obtained: ##STR1## The compounds are useful as lubricants.

DESCRIPTION OF THE INVENTION

The present invention relates to novel fluorinated compounds, and to aprocess for preparing them.

More particularly, it relates to three novel fluorinated compoundsobtained by reacting3,3,4,4,-tetrafluoro-2-(trifluoromethyl)-1,2-oxazetidine: ##STR2## witha Lewis acid.

The above said oxazetidine of formula (I) is a known compound, describedby D. A. Barr et al. in J. Chem. Soc. 1955, 1881.

It has now been discovered, according to the present invention, thatsuch compound reacts with a Lewis acid generating three novelfluorinated compounds.

An object of the present invention is to provide the said novelfluorinated compounds.

Another object is to provide a process for preparing them.

The first object is achieved by providing the following three novelcompounds:##STR3##3,3,5-trifluoro-2,5-di(trifluoromethyl)-4-(1,1,2,2,2-pentafluoroethoxy)-1,2,4-oxadiazolidine;##STR4##2,2,4,4,6,6-hexafluoro-1,3,5-tris(1,1,2,2,2-pentafluoro-ethoxy)-1,3,5-triazine;##STR5## N,N-bis(trifluoromethyl)-N-(1,1,2,2,2-pentafluoroethoxy)-amine.

The compound (II) which is a liquid with a boiling temperature of 75°C., is useful as a lubricant, as a heat transfer medium, and as a testfluid for electronic components.

The compound (III), a solid compound with a melting point of 60°-61° C.,is useful as a lubricant.

The compound (IV), a low-boiling liquid, with a boiling temperature of27° C., is useful as a test fluid for electronic components, and as aheat transfer medium.

These three compounds are prepared simultaneously by the processaccording to the present invention. This process is characterized inthat 3,3,4,4-tetrafluoro-2-(trifluoromethyl)-1,2-oxazetidine (I) isreacted with a Lewis acid.

The reaction is usually carried out at a temperature within the range offrom 0° to 100° C., and preferably from 10° to 40° C.

As the Lewis acid, SbF₅ is preferably used.

The molar ratio of the Lewis acid, computed as SbF₅, to the oxazetidine(I) is usually with the range of from 0.1 to 2.0, and preferably from0.9 to 1.1.

The reaction may be carried out batchwise, inside an autoclave, underthe autogenous pressure of the system. The reaction time is generallywithin the range of from 1 minute to 24 hours.

At the end of the reaction, the reaction mixture is treated with aneutralizing agent in order to neutralize SbF₅.

As the neutralizing agent, is particular NaF is used. The molar ratio ofsuch an agent, computed as NaF, to SbF₅, is usually within the range offrom 1 to 50; and preferably from 5 to 15.

The following example is given for the purpose of still betterillustrating the invention but without limiting it.

EXAMPLE

Inside a Teflon tubular reactor having a volume of 20 ml provided with avalve, the following compounds are condensed in the same order as shown,at the temperature of liquid nitrogen (-196° C.):

2.88 g (13.3 mmol) of SbF₅ ; and

2.90 g (14.6 mmol) of oxazetidine (I).

The oxazetidine was prepared by reacting

    CF.sub.3 --N═O

with CF₂ ═CF₂ (D. A. Barr et al., J. Chem. Soc. 1955, 1881).

The thus-charged reactor is maintained at 20° C. for 12 hours.

To the raw reaction mixture, cooled down to -196° C. and under ananhydrous nitrogen atmosphere, 5.60 g (133 mmol) of fine NaF powder isadded.

The thus-charged reactor is maintained at 20° C. for a further 24 hoursand, in order to achieve a good solid-liquid contact, is repeatedlyshaken.

The reaction products are recovered by being transferred, under a lowpressure (10⁻³ torr), from the reactor into a cold trap maintained at atemperature of -196° C.

This step requires 24 hours.

The mixture of the reaction products is distilled under a pressure of10⁻³ torr.

The vapors coming from the distillation kettle are made to flow throughcold traps maintained at temperatures of -50° C., -85° C., -110° C., and-196° C.

Inside the trap at -50° C., 145 mg of compound (III) is collected, witha molar yield of 5% relative to oxazetidine (I).

The compound (III) was characterized as follows:

Mass spectrum: chemical ionization (CI), CI gas=CH₄, m/z 598 (MH⁺) 578(MH-HF⁺).

Infrared spectrum: main absorption bands (cm⁻¹): 1391 (d), 1332 (d),1289 (F), 1242 (f), 1180 (m), 1089 (f), 946 (m).

¹⁹ F-N.M.R. spectrum: (internal reference: CFCl₃ ; solvent: CDCl₃ ;temperature=50° C.). ##STR6## A=84.7 ppm B=93.0 ppm

C=84.7 ppm

NOTE: These represent chemical shifts of F atoms in the relative groupswith reference to the internal compound CFCl₃.

Inside the trap at -85° C., 1.37 of compound (II) is collected, with amolar yield of 47% relative to oxazetidine (I).

The compound (II) was characterized as follows:

Mass spectrum: chemical ionization (CI), CI gas=CH₄, m/z, 399 (MH⁺), 379(MH-HF⁺).

Infrared spectrum: main absorption bands (cm⁻¹): 1362 (d), 1315 (m),1282 (m), 1246 (f), 1225 (f), 1179 (m), 1120 (m), 1098 (f), 942 (d).

¹⁹ F-N.M.R. spectrum: (internal reference: CFCl₃ ; solvent: CDCl₃).##STR7## A=-111.6 ppm B=-82.3 ppm

C=-66.7 ppm

D=-78.7 ppm; -83.1 ppm (AB system)

E=-90.1 ppm; -95.2 ppm (AB system)

F=-84.7 ppm

NOTE: These represent chemical shifts of F atoms in the relative groupswith reference to the internal compound CFCl₃.

Inside the trap at -110° C., 0.42 g of compound (IV) is collected, witha molar yield of 10% relative to oxazetidine (I).

The compound (IV) was characterized as follows:

Mass spectrum: chemical ionization (CI), CI gas=CH₄, m/z, 288 (MH⁺), 287(M⁺), 258 (M-F).

Infrared spectrum: main absorption bands (cm⁻¹): 1361 (d), 1319 (f),1272 (f), 1240 (f), 1218 (f), 1183 (f), 1095 (f), 1035 (d), 970 (m), 713(m).

¹⁹ F-N.M.R. spectrum: (internal reference: CFCl₃ ; solvent: CDCl₃).##STR8## A=-67.9 ppm B=-94.3 ppm

C=-85.0 ppm

NOTE: These represent chemical shifts of F atoms in the relative groupswith reference to the internal compound CFCl₃.

Inside the trap at -196° C., 0.25 g of oxazetidine (I) is collected.

What is claimed is: 1.3,3,5-trifluoro-2,5-di(trifluoromethyl)-4-(1,1,2,2,2-penta-fluoroethoxy)-1,2,4-oxadiazolidine:##STR9## 2.2,2,4,4,6,6-hexafluoro-1,3,5-tris(1,1,2,2,2-pentafluoroethoxy)-1,3,5-triazine:##STR10## 3.N,N-bis(trifluoromethyl)-N-(1,1,2,2,2-pentafluoroethoxy)-amine:

    (CF.sub.3).sub.2 N--O--CF.sub.2 CF.sub.3.